<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>
</head>
<body>
    <div id="app">
        <ul>
            <li v-for="(item,index) in msgList" :key = index>{{item}}</li>
        </ul>
        <input v-model="message">
      <h1>{{message}}</h1>
      <button v-on:click="add">添加</button>
      </div>
      
    <script>
        var app = new Vue({
            el: '#app',
            data: {
                message : '',
                msgList: []
            },
            methods: {
                add() {
                    this.msgList.push(this.message)
                    this.message = ''
                }
            }
        })

        
    </script>
    
</body>
</html>